甘麦大枣汤对慢性应激抑郁模型大鼠学习记忆及海马突触可塑性的影响

Effects of Ganmai Dazao Decoction on Learning, Memory and Hippocampus Synaptic Plasticity of Chronic Stress Depression Model Rats

【目的】探讨甘麦大枣汤对慢性应激抑郁模型大鼠行为活动、学习记忆及海马突触可塑性的影响。【方法】将Wistar大鼠随机分为4组，即空白组、抑郁模型组、氟西汀组（5．4mg／kg）、甘麦大枣汤组（3．84g／kg），采用慢性温和不可预见性应激加孤养的方式建立抑郁模型，造模同时灌胃（ig）给药，连续21d，观察甘麦大枣汤对模型大鼠水迷宫测试的影响，采用免疫组化、Western-Blotting的方法检测各组大鼠海马突触素I（SYNI）、突触素（SYNA）、脑源性神经营养因子（BDNF）的表达水平并比较。【结果】与正常组比较，模型组大鼠水平及垂直活动的得分明显下降（P〈0．01），逃避潜伏期（EL）、目标象限潜伏时间显著增长（P〈0．05），SYNI、SYNA、BDNF的表达显著下降；与模型组的结果比较，甘麦大枣汤能缩短模型大鼠的EL（PG0．05），并能缩短目标象限潜伏时间（P〈0．05），增加模型大鼠海马SYNI和SYNA的表达（P〈0．01或P〈0．05），促进BDNF的含量增加。【结论】甘麦大枣汤能显著改善抑郁模型大鼠的学习记忆能力，其机制可能是通过提升其海马突触可塑性而发挥作用。

[Objective]To investigate the effects of Ganmai Dazao Decoction on learning, memory and hippo- campus synaptic plasticity in chronic depression model rats. [Methods]Wistar rats were randomly divided into 4 groups： the control group, he depression model group, the fluoxetine group （5.4mg/kg） and the Ganmai Dazao Decoction （3.84 g/kg） group. Depression models were established by chronic mild unpredictable stress and soli- tude. The fluoxetine hydrochloride and Ganmai Dazao Decoction group were intra-gastrically administrated （ig） with corresponding drugs once a day for 21 days, and the depression model group was intraperitoneally injected with water. Then, we observed the effects of water maze test in model rats with Ganmai Dazao Decoction. The ex pression of SYN I （synaptophysin I）, SYNA （synaptophysin）, and BDNF （brain-derived neurotrophic factor） were detected by the immunohistochemistry and Western-Blotting methods. [Results]Compared to the control group, the horizontal and vertical activity scores of the model group decreased significantly （ P 〈0.01 ）. However, the escape latency （EL） and target quadrant latency increased significantly （P 〈0.05）, and the expression of SYN I, SYNA, BDNF were reduced dramatically as well. Compared to the outcomes of the model group, Ganmai Dazao Decoction reduced the EL （ P 〈0.05）, shortened the target quadrant latency （ P 〈0.05） and increased the expression of hippocampal SYN I, SYNA and BDNF（ P 〈0.01 or P 〈0.05） of the model rats.[Conclusion]Gan- mai Dazao Decoction can significantly improve the learning and memory abilities in chronic depression model rats, which may play a role in the promotion of hippocampal synaptic plasticity.